Modern Warfare 2 surpasses $1bn in retail sales

Activision's Call of Duty: Modern Warfare 2 has surpassed $1 billion in retail sales worldwide since launch in November.

In its first five days on sale the game made an estimated $550 million worldwide, out-pacing theatrical gross figures of movies such as The Dark Knight, Avatar and Harry Potter and the Half-Blood Prince, according to Activision.